Pressure vessels are used within rockets, missiles and other aerospace vehicles for containment and storage of pressurized fluids. One such use of pressure vessels within rocket motor sections is to provide a source of pressurized gas (such as nitrogen) for use in attitude control systems (ACS) to steer and stabilize rockets in flight. Pressure vessels hold gas therein at extremely high pressures (e.g., 5000 to 8000 psi) and correspondingly require robust structure for safe storage. Pressure vessels are constructed with durable materials including steel, titanium and the like. The thickness of these materials is increased at known stress concentrations to ensure the pressure vessel does not fail before or during flight. Further, the materials of the pressure vessel are thickened to ensure the pressure vessel maintains its shape and does not unpredictably deform. A bulging pressure vessel may impinge against other components in the rocket motor section including the aerodynamic shroud covering the motor. Increasing the thickness of the vessel materials correspondingly increases the pressure vessel weight and the overall weight of the rocket motor section, and also reduces pressure vessel fluid volume. The increased weight diminishes motor section performance (range, responsiveness to course corrections and the like).
Additionally, pressure vessel shapes are fit within the rocket motor section and the space needed for a pressure vessel competes with space needed for other components. The pressure vessel shape is also chosen to provide strength and minimize stress concentrations within the vessel. In one example, a toroid with a circular cross section is used because of the known strength of a circle. A pressure vessel using a circular toroid occupies significant space within a rocket motor section and does not readily fit adjacent to components having shapes that do not correspond to a circle or toroid. Additional space is thereby provided between the other components and the pressure vessel to fit the pressure vessel within the motor section. The added space to house the pressure vessel increases the motor section size and weight and further degrades the motor section performance.